Photographic apparatus.



" lowing, taken in connection with the accom- Appuauan mea n! 11, 191s. i mm1 110.21341.

To all 'whom it may concern.'

Be it known that 1 JOHN A. Rrcxm'rs, a citizen of the United tates of America, and a resident of Rochester, in the county of Monroe, in the State of New York, have invented new and useful Improvements in Photographic Apparatus, of which the folpanying drawings, is a full, clear, and exact description.

This invention relates to certain improvelments in photographic apparatus, and more particularly to the shutter operating and controlling mechanism and correlated parts' ofa camera.

The main object is to render the timing of the exposure automatic and of uniform duration ependent upon the will of the operator.

' Other objects and uses relating 'to s ecific parts ofthe apparatus will be broug t` out 1n the following description.

In the drawm s- Figure 1 is a ont elevation of an'cpen photographic camera embodying the varions features ofmy invention. i

4Fi 2 is an enlarged front face view of the s utter case, omitting the time index, setting lever and release lever, and showing the lens tube in section.

Fi 3 and 4 are sectional views in differanes through the shutter case at right ent lp an es to its axis, showing the shutter contro ling mechanism in elevation in Fig. 3, and the shutters in Fig..4 to ether with the driving mechanism for saids utters andthe diskV carrying the detent which coperates -with the release lever for controlling the operation of the motor,

Figs. 5 and 7 are enlarged detail sectional views taken, respectively, on lines 5--5 and 7 -7 Fig.A 2.

Fig. 6 .is` an enlarged inverted elevation of* the release lever, timing levers, showing also the setting and tri ping disks, a portion of the lShutter case eing shown in section, the detent coperating with the release y. lever for preventing Vthe action of the motor being also shown in section. p

Fig. 8 is adetail sectional view taken on line 8 8, Fig. 3. Y Fig. 9 is a detail elevation of a portio of the release lever and timing disk mounted thereon. y

Fig. 10 is an enlarged inverted View Qi the timing index Fig. 11 is an enlarged sectional view taken on line 11-11, Fig. 3.

Fig. 12 is an enlarged sectional view through the shutter case at right angles to its axls, showing a modified form of retarding device in which the magnet acts directly upon one of the shutter blades.

Fig. 13 is a detail elevation of the electromagnet and coperative shutter shown in Fig. 12.

Fig. 14 is a detail sectional view taken on .line 111-14 Fig. 2.

y Specification of Letters Patent; Patented Dec. 18, 1917.` i

soA

My invention is illustrated as used in connectlon with an ordinary photographic camera of the extensible type having the usual plate holder and ground glass (not shown), and is provided with a shutter case -1- mounted in a suitable frame -2- which is attached to the front end of the extensible portion -aof the case and is adjustable vertically in the usual manner in a suitable i frame -'B-, the latter bein guidedinia' for back-` central longitudinal way Ward and fOlWard ad'ustment of the slitif` properly fangs Y ter case and lens hol er to the camera upon an object. l The front and rear plates of the shuttercase are provided with the usual central lens tubes and co-aXial sight ,or exposure openings, said case being divided by a partition .-3- into separate compartments -4- and -5, the partition 3- being providedy with a central exposure opening coaxial with thosein" the front and rear plates.

The shutter mechanism is mounted `within 4the compartment.-4 and is somewhat similar to that set forth in my Patent No. 778,334, issued Dec. 27, 1904, in that it consists of a series of, in this instance lfour, shutter blades 7 and -7 'and S- and -8-, arranged in pairs, those of each pair bein diametrically opposite each other and suita ly pivoted to the partition -3 and rear plate of the case at the outer side of the opening +6- to swing to and from a osition across said opening, each shutter glade-bein provided with a co-axialpinion 9- mes in with a central toothed ring 10,-- by which rotary motion is transmit. ted from one blade to theother.

All of the shutter blades are preferably made of thin sheet metal and of suiicient combined area to effectively close the central exposure opening in the toothed ringI -10 when in their closed postlOnS, the blades -7- and -7- being disposed in different but juxtaposed plahes and of sufficient width to overlap when closed, and for this purpose are approximately elliptical in plan and pivoted in their shorter diameters near one edge, the shorter diameter of' each blade being somewhat greater than the distance from its axis to the axis of the shutter case, while its longer diameter is greater than that of the opening in the toothed ring -10-.

The shutter blades -8- and -8- are approximately quadrants of a circle and of sufficient radius to cover any open space which may exist between the adjacent edges of the blades --7- and --7'- when the blades are closed to exclude light, said blades -8- and 8- being disposed in the same plane just at the back of, but in close proximity to the rear blade -7'-`, as shown more clearly in Fig. 7.

The 'object in making these particular forms of shutters and mounting them in the manner described is to ca use them to open from the periphery toward the center of the exposure opening and to close in the same order, but it is evident that various other formsv of shutters may be used without departing from the spirit of my invention as will be obvious at the concluslon of this description. 4

Shutter. motor mechanism In the use of the specific form of shutters just described, suitable motor mechanism ision -11- meshing with a somewhat largerdriving gear -12- which is journalcd upon a hub I3- on the partition -3- and is held in place b a clamping screw -14-'-, as shown more c earlyl in Fig. 5 so as to lie close to the rear face of said partition .or between the partition and shutter plate- This driving gear l2- is provided -with a-plurality of, in this instance four, recesses rampas locked for the purpose of forcing it out of said opening and, therefore, out of interlocking engagement with the gear l2- against the action of the spring -plate -18- when the disk '-17- is rotated 1n one direction against the action of a motor spring 20- in setting the motor disk preparashown in Fig. 3, so as to rotate the motor disk opposite to that indicated by arrow The outer end of the hub of the-disk 17 protrudes through the front plate of the shutter case and is preferably angular in cross section for receiving an operating lever 22- which is held in place by a clamping screw -23, as shown in Fig. ,5.

The ratio of the gear 12.- and pinion -11- is, in this instance, four to one, and it, therefore, follows that if the shutters are normally held in\.a closed position and the gear 12- rotated one-fourth of a revolution, or the distance from one of the re cesses 15- to the next adjacent recess, the

shutters willbe rotated one complete revolution, or opened from their normally closed positions and reclosed in one operation, and that this movement of the gear 1.2- through a quarter turn is produced by the spring motor -20- when placed under tension by the rotation of the lever 22- and disk -17- a quarter turn from its normal position in the direction indicated by arrow v, Fig. 3, thereby registering thepawl- 16- with the next adjacent opening or' recess 15'- so that if the setting lever 22- is then released, it willv return fthe disk -17- and lever 20-"- to its starting position. and thereby cause thepawl -16- or openings l5-- spaced uniform distances 'to rotate the gear l2- in the direction apart about its axis to form ratchet teeth for engagement by an operating pawl -16 which is movable' through a -'de ope in the main driving or'motor disk 17f an, is secured to a sprlng plate -18- on the outer face of the motorA disk -'17-., as shown in Fig. 5, the inner end of the pawl 16- be-l ing passed through anelongated slot -19`- in the partition -3 concentric with the axis o'f movement of the driving gear -12- and motor disk -17-, the latter being journaled in suitable bearings on the part1- tion 3+ and outer plate of the shutter case '1- co-axial with the driving gear -12.

One side of the inner end of the. pawl #-16- is beveled to cause it to ride against one of the` openings the adjacent side of any l5- with whichft may be normally-1116er" indicated by arrow -yone quarter turn,

'revolution unless stopped in their open positions for time exposures in a manner-herein-` after descrlbed.

Shutter 'stop and release mechanism.

wd-release lever 24.- iS pivoted to a hub 13o 25 on the partition within'the` compartment and is held in place by a clamping screwf-26- said lever being provided with a stop shoulder #-27- which pro'ects throu hfthe bearing' ei gear ,-31- 'meshing with la `gear --32- of similar size and preferably secured to the rewith sthat` any movement which .is imparted to; this shutter will be transmitted Vto the disk It, therefore, y follows that if the empl shoulder -27- of the release lever '-24- is nbrmallyin the ath of movement of the `L detent 28- the isk 29- and o rating mechanism therefor including all t e shut- `ter bladeswill-be held in a normal position" of rest, in this instance, in their closed posi- It is equally evident that if the release lever -24 were operated to force the stop shoulder -p--27-4 out of the path of move- :ment of the detent -28- and heldin this '.posi'tion, the shutters wouldbe moved some distance beyond a complete revolution which lwould, of course, be objectionable, and in .p lever-24- to have a slight rocking move-f ment as limitedv by a slot .-35-,- and pin -36-, said diskbein located on the outer face of \the lever an is provided with a rearwardly projecting stop shoulder 3T-.- normally out'of,the pathfof movementlof 'the detent -`2.8- 'and a little to Vone side of Y -a radial line o= vthe disk -33- ,plane of the stop s oulder 'o take the place of said'stopA n the release lever is tripped ing 4engagement with the detent 2S- in a`- manner hereinafter described, that is, as soon as the shoulder -27- is withdrawn from holding en agement with the detent 28'- to allow t e shutters and their operating mechanism to turn from their normal positions, the shoulder -37- is moved into position tobe engaged byl the detent --28--fy 1n case the releaseilever Q4- `should be held from its normaL position, in which ease' the stop shoulder 37 wouldl serve the same purpose as 'the stop shoulder -27- in limiting the' movement ofthe shutters to n secured by a clampin one ,revolutiomuntil' the release lever was allowed to return to its normal position by its-retreating spring, as -38.

Suitable means is provided for' preventingV the ,operation ofthe release lever when the setting lever isin its normal position consisting, Ain this instance, of a yielding extenprojection or abutment 40- on the motor disk -1' normally in the pathof movement .of the end ofthe extension -39-, Ias

ment"-40- `being beveled on one side to allow itto pass under the spring armor extension 39 upon the 'return of the Vmotor disk -17-by the spring -20-.

`shown more clearly in Fig. 3, the end abut- Any suitable device or devices may be employed for tripping-the release lever -24 at the will of the operator, such for example N as a flexible plunger "41- passing through -a flexible .tube '-42-- on the periphery' of the case -1-- and adapted, to engage a shoulder- 43,- on the lever, or it tn ay `be operated electrically through the medium of upon the frame B- and having its Aplunger connected by a link -44' to a lever -145-4- which is screw -46- to a revoluble disk -47- s own by dotted lines in Fig. 3, and by full lines in This disk isprovided with a uced eenf .tral portion journaled in a suitable `bearing in the front plate of thecase -1- with its 4 vmain body. at the inside of said. plate, Vor within the compartment -5- and provided with astud 4B-- adapted -to engagean for tripping the latter as .the disk is rotated to the left, Figs. 1 and 3, by the downward movement of the lever 445- when the-solenoid is energized. y This solenoid is electrically connected suitable binding posts -51- which in turn may beV connected to any suitable battery circuit having an electric' switch therein, not necessary to herein illustrate or describe.

Automatic retardmecItavriz'arm.

The .opening and closin o f the shutters j through the medium off t e motor mechanism as controlledl by the release lever is practically instantaneous, and while-I am.`

aware that various forms of timing devices Vhave been heretofore proposed ,to cause the shutters to .remain open greater or less intervals of time according' to the will of the operator, itis desirable tq provide the apparatus with means wherebyl -the closing movement ofthe shutters may be automatically retarded to'a greater or less degree, as preias lll

viously regulated by the operator so that when the instrument is once set for -a prede-` termined time of exposure,all exposures will be of the same lduration for that particular setting, and I have found the w.

torque or magneticl drag acting upon an electric lconductor moving in a` magnetic eld may be used with" great ,eiiiciency and economy for this purpose, and while this part vof my invention is based broadly upon-any means which mayl exert a retardlng influence upon any kind-of a motor actuated shutter, or upon any part of the apparatus moving in synchronism therewith, I have shown in Figs. 3 and 11 a small permanent magnet 52- ladjustably secured by 'clamping screws --53-`l to the partition 3 at one side of the opening -6- therein' opposite the release lever -24- and arranged'so as to exert a retarding infiuence upon a rotary metal disk -54-, as shown in Figs; 3 andV 7,

or upon one of the metal shutter blades as -7-, in a manner somewhat similar to' that shown in Figs. 12 and 13, except that in the last named figures, I have shown an,

electro-magnet '-52- having' poles of opposite polarity disposed at opposite sides of the disk sothat the latter may travel in the magnetic field which exerts a greatenor less 2.5 drag upon the disk tending to retard its movement.. v

In like manner, the opposite poles of the permanent magnet `-52- are located at o'pposite sides ofthe disk -54-. to exert a retarding action thereon, due to the magnetic drag produced. bythe movement of the `disk through the magnetciield. y

In this particular instance, thedisk54 within the compartment #-5- of the case -1-, the end pmion of the gear train meshe .ing with a toothed segment -56- which is ,pivoted at -57- to a lever 5S- and is -provided with a heel extension F59 havmg a rearwardly y projecting stud or pin 60- projecting through an elongated slot -61-, the latter being concentric with the o axis of the pivot -57-, said se lent being lever -58- by a retracting spring -62f-.

The lever --'58- is pivoted to the partition '-3- by apivotal bolt or screw 63rcoaxial with the axis of the pinion which opposite end is pivotally connected to a link -64- by which the lever -58- and toothed rack -56- mounted thereon may be rocked about the axis of thepivotal pin G3- in a manner presently described.

The stud or pin 6U-'.- on the heel of the toothed segment 56 not only rojects, -.through the curved slot 6lin t e lever -58- but also extends through an opening #65- in the partition -3--,an'd. some d1stance beyond the inner face thereof so as to permit- 1t tobe brought into the path of movement of a cam 66- Which is pivoted at 674- to the partition 3.- closeto the '65. face thereof, saidvcam bemg secured'to relatively to the lever a is ada ted to be y driven at relatively high operated in one direction relatlvely .to the meshes with the toothed rack -56- and' its the shutter -7- co-axial therewith to be rotated thereby, asi shown .more clearly in Fi .4`and7. j v

t is now clear that if thelever -58-ris rocked toward the center of the shutter case by the link the smeer pin I y will-be b'muhnclosef'wtu'axis of the 'cam' is then inits normalI position with the. shutters'closed and the high point of the'camy projectingtowardthe center of 75 the shutter case, as shown in Figs. 2 and 3, and that when the release lever ,-24f-` is tripped from its normalpositionafter the sprmgmotor has' been 'placed under va greater or less degree'by the magnetic drag or torque acting upon the disk, therebycaus-- 95 ing a correspondin retardation of the'clos inmovement of t 'e shutters. Y

his period of retardation may be varied according to the positionl of the stud. or pin l -lGO- relatively to the 'axis' 'of thecam 100` -66-, as aiected by the adjustment of thel lever 58- through the vmedium of v.the link 64-, the period of retard being greatest when the stud +604 is shifted nearest to the axis of the cam and least when farthest from'said axis, for the 'reason that when nearest the axis, the -toothed segment 56 will be moved through a greater arc' and will begin with the opening movement of the shutters and `continue through the closing movement of the shutters as the segment is returned by the retracting sprin -62-, while on the other hand, fthe stu-d or pin is set farthest from the axis, the arc of movement of the toothed segment -56- 115 wll be lessand when shifted to its extreme outermost position beyond the pathof travel ofthe cam, the toothed segment -'-56- and disk 5l driven 'therebyvwill remain at rest, and therefore,.there will be no retarda- 120 tion o f the shutters whichA will be moved through' one revolutioni and will open and close instantly for'instantaneous exposures.

vBy the use of this retarding means, I amM able'mo obtain a uniform time exposure un# 125 der allyconditions, the duration of the exposure depending upon'the position of the stud orpin 60- relatively to the .axis vof the cam 66-. Y

- suitable means may provided for 18o operating "the to ,set the pin` 60`-, and for this purpose, the inner end of the' link is forked to receive a guide in 68- on the inner face of the front p ate of the shutter case -1-, one of the arms Y of the fork being proyidedwith a forwardly projecting pin 69.- rojecting through a Iandinto a` spiral or eccentric ve -71- n the inner :face of an externa disk v72-. f

'This disk -72- is journaled on a forwardly projecting hub -73- o'n the front plate of the case '-1- and its periphery is preferably knurledto permit it to be turned.

readily by hand. 4

The front face Vof lthe disk is suitably graduated with a fixed index finger --74-vwhich is secured'to, an angular n rtion of 4the hub-43-n and together wit the is held in place by a clam ing screw 75-. l

The'opening -70- t rogh` which the ".tion will be transmitted to-the .link n64- y so,

of extension of the so that as the disk -72` is rotated, longitudinal mothrough the medium of the pin and .cam groovee-.fflthereby effecting a responding rocking movement of the-lever mi i for the purpose previously explained.I .y y

" Manually controlled timing In addition to the automatic tardin `mechanism just previj 'yf 'de-" scribed suitable means is providedfor con.4

trolling the time exposures at will, and for this urpose, I have provided a palrof timinA evers +76 and -77-., the lever a lease leverg-'f24-f to move relativeljn'therey.to against theaction of a'retracting ring tially extending-arm 80- .for interlock? ing .engaemelitwith a' pin thef- -flzont n a lattenbe'ing pivoted. at S2-ftofthe of :th'ev timing lever f4-77- 2th" iront face of the partition and is yieldingly held in its outermost sposition by a'retracting own more clearly in Fi 3. t 4 'ghe timingV lever -76- is provided with an upstanding shoulder S4-,- adapted to' be' engaged bya stud or` in' -85--on the inner face ofv the'disk 2+- and project' ing linwardly jthrou h fa" concentric l'slot as 'shown more clear yin FigrZ. A portion of the cam groove thest from the axis of the disk is con-f centric with said axis so that when the disk is adjusted to `throw the automatic retardvingmechanism out of action, it may still be moved a distance withoutactuating and .-77- to their 'startingl Ylever -76 is provided wit 4 `scription that whenthe timin such retarding mechanism, and the stud or pin --7 is so arranged as-'to engage lthe upstanding shoulder -84- on the timin lever -76- as soon'Aas the pin 69+- 0 the retardin device enters .the concentric upon a continued movement of the disk 72- in the-same direction will cause the j timing lever #f77-.-

shifted'from its normal position to` permit the motor spring #20-l to operate the shutters, the free end of the timing-lever 77- will be rocked partially across the front face of the disk 29'- and will `bring a portion thereof, as -87-, into the path of movement of the shoulder 28-' on said disk when the latter has completed sub-` stantially a .half revolution, thereby permit.

ting a correspo v shutters, 4.leaving the latter'in an open position. y

When the disk 72- is set in the mannding half revolutionl of the ner just described for time exposure, its pin or stud 85- will still be in engagement .with ithe shoulder 84- toahold the lever the lever -7 under which conditions, the shoulder 84- will benearl in a vertical position to allow the `re lease ever `--24- and also the timin levers tively 'to the shoulder --85 on the disk Inoider that the shutters maybe held in theiio positions after'the return of the releaseever 241- and timing levers '-76- positions2 the stop shoulder 88 which is movable into the path of the shoulder S5- just before the" rtion. f-87- of the lever T7-"is with n wn from its holdin position on the return ofthe release lever liy its retracting spring- -38", so that at the end of a predev f time exposure, the release lever may again operated through either of itsvtripping devices, previously described, to

withdraw the stop shoulder 8S- from holding `eil gement with' the' shoulder 85-, there y allowing the disk -29 to complete its revolution 'under the action of the Aspring motor `20- for closing `the an additional n sin be evident from theforpegoing de;

and -77 are set` `for inde Y ite time exposures,the automatic timing mechanism is revented from operation, while on the other andrwhen the automatic timing mechanism nev'ers -76- is adjustedfor use, it will be impossible to` f set' 'the levers and -77- for 'indefinite exposures, thus making the operation of one timin mechanism Adepen ent upon the position o the other.

Referring again to the retarding mechanism, and more particularly 'to the electromagnet, shown 1n Fig. 12, it may be desirable under some conditions to pivot the magnet at -90- to the frame or shutter case and to vary itsretarding influence upon the disk -7- by shifting `its position,

which may be done by the disk 72- vthrough the medi um Nof the link G4- by connecting said link at a point as -91-to one of the poles of the magnet, or if a rheostat, as -92- is to be used to control the current'energy of the electro-magnet and thereby control its retarding influence upon the shutter -7-, the' movable arm as -93- of the rheostat'may also be connected as at -94-- to the linkl It is obvious that-the rotary disk '54- or its equivalent and the magnet -52- or '-2 may be used in connection with panv oramic 'cameras for regulating-the speed of L movement of one-of the motor-driven exposure-controlling elements, and thereby establishing uniform time exposures under a predetermined relative adjustment of the disk and magnet, and therefore, I do not` wish to limit this part of my invention toits use in connection with shutters; l.

For example, the axial spindle upon which the disk -54- is mounted might bethe turning pivot of the swinging lens holder `or iilm support of any well known form of panoramic camera, or said spindle might be `geared to either of those swinging parts in jects of my invention, I do not Wish tolimit:

any other suitable manner within the range of mechanical skill, whereby the movement of such swingingpart would transmit motion to the disk. A

While I have shown and describedspeciiic mechanisms for carrying out the various obmyself to the-precise'construction shownl and described, because it is evident that the vari- Y. ous mechanisms 'may be varied materiallyv withoutdeparting from the spirit of my 'in-Vv 1. In a photographic' apparatus, :motoractuated-parts including a rotary shutter,

vention.

What I claim is:

and' magnetic; means acting -upon one of said .parts for partially counteracting the inuence of the motron the shutter.

l 2. In combination withv motor-driven 1 mechanism including the rotary shutters of .a camera/and a ma et, a part ofsaid mechanism being movab ein the {ieldof the magnet.; l

3. In a photographic apparatus, the com- V'bination 'with rotary shutter blades and means for driving them in one direction only, of electric means for partiallyjcounter.-

. bers to Vopen t act' the e'ect of the means upon the utter blades V 4.- In a photographic apparatus, a magnet vhaving its poles in opposed relation, and

motor-driven exposure-controlling mechanism including` a rotary shutter havin a portion thereo revoluble between said po es.

5. In a photographic apparatus, the com-y bination with motor-driven exposure-controlling means including a plurality "of shutter blades, of coperative magnetic meansgerning the speed of movement of.. the

named means. 6. In a photographic apparatus', means for timing an exposure comprising a plurality Vof rotary shutter blades, a motor-driven electric conductor, and coperative means 7. In a photographicshutter, the combina- 'tion of a 'shutter case having an exposure opening, 'a plurality of rota -members 1n said case, some of which mem ers are` shutters normally closin said opening, means including a. spring. or rotating said meme shutters and return them to their closed positions in one continuous movement, and magnetic means coacting with one o f the rotary members to retard the speedof the shutters during said continuous movement.

8. In a photographic shutter, the combifor exerting magnetic influence upon said conductor to control its speed of movement.

nation of a shutter case having an exposure j opening, a plurality of rotary membersin vsaid case, someV of which members are shutters normally closin said opening, means including a. springl or rotating said memto their closed positions in one continuous bers toopen the shutters and return them movement, 'magnetic means coacting with one, ofthe rotary members to retard the speed of the shutters during said continuous movement, and automatic means for stopping the rotary members at the end of' said movement.

9.V In a photographic shutter,'the combination of a shutter case having anexposure opening, a plurality of rota members-.in

'said,case, some'of which mem ers are shutters normally closin vsaid opening, means including a' spring orrotating said members to open theshutters andreturn them to.

tortheir closedlpositions in one continuous v'n`iovement,' means for detaining said members 'against movement by the spring, means' operable at will for tripping the detaining means', and magnetic means for retarding the speedof movement of said members by the spring.v i

10. In a photographic shutteigfthe' combination of a shutter case having an exposure opening, a plurality of rotarymembers in said case, some of whichmem r`s are shutters normally closing said opening,-'means including a spring for rotating said members to to their closed positions in one continuous movement, means for detaining said members against movement by the sprin means operable at will for tripping the etaining means, magnetic means for retarding the speed of movement of said members bythe slpring, and automatic means for restoring t e detainin means to stop said members at the end of sald continuous movement. 11. In a photographic shutter, the combination of a shutter case having an exposure opening, a plurality of' rotary members in said case, somev of which members are shutters normally closin .said opening, means including a s ring, or rotating said members to open t e shutters and return them to their closed positions in one continuous movement, means `for detaining said members against movement by the spring, means operable at will independently of the shutter members for placing the spring under increased tension, `means for locking said 26 spring-tensioning means in its tensioning position to one of the first-named rotary members, means operable at will for tripping said detaining means to allow the rotary members `to be operated by the spring 30 an to permit the spring-tensioning means to be returned to its starting position, automatic means for restorin the detaining means to its detaining position for stopping the shutters at the end of said continuous movement, and magnetic means for retard'- ingthe'` speed of said members during said continuous movement. v

12. Ina photographic shutter, the combination of a shutter case having an exposure 40 opening, rotary shutters normally closing, l said opening, motor-driven means for o ening said shutters and returning them to t eir closed positions in one continuous operation, a retarding device includingba magnet and an electric conductor mova le in the lield of said magnet, means for transmitting x 4motion, from the shutter-actuating means vto lsaid conductor including means for varying .the period of operation yof the conductor during said continuous movement ofy the.

shutters.

1'3. In a nation of a openin a plurality of normal photographic shutter, the combishutter `ease having an e ure y close shuty,li ter `bla es pivotally mounted within the case `open the shutters and return them relatvel means for 'transmitting ping the locking around said opening, and means for', opening said blades and returning-them to their closed position in one continuous operation comprising a rotary, spring-actuated driving member and a rotary drlven member, the driving member being adjustable rotarily vided with means for interlocking engagement therewith at different `points around its axis, and means o erable at will for effecting said rotary adjustment of the driving member against kthe action of said sprin to cause its interlocking engagement witg the driven member, whereby both members will be rotated by the spring to operate the shutter blades when is released.

14. In a photographic shutter,the combination of a shutter case'having an exposure opening, a plurality of shutter blades pivotally mounted within the case around said opening and normally closed, a rotary, springactuated drivingmember, driven motion from `said driving member to the shutters for openin the same and returning them to their close positions, said driving member being adjust-i able rotarily relatively to the driven means for tensioning the spring and provided with means for interlocking engagement with dif- .ferent portionsof one of the parts of the driven means for im arting motion to. said driven `means after t e sprlng is placed under tension a locking member coperating with one of the parts of said driven means for detaining the same against operation by the driving member, coperative means between the driving member and lockin member for preventing the tripping of sai locking member when the driving member is in itsnormal position and for releasing the locking beris adfusted to tension the spring, and additiona means operable atwill for tripmember to release t e drlven means an by the driving member when the latter is released after tension'in the spring.,

In ,witness whereof If my hand this 30th day of April, 1915.

JOHN A. RICKETTS. Witnesses:

Crus. O.- Woman, LonnN N. Boheme.

member when the `driving mernto the `,driven member and proi the last-named means I lhave hereunto set permit it to be operated 

